In vivoSPECT/CT imaging and biodistribution using radioactive Cd125mTe/ZnS nanoparticles

Radioactive cadmium telluride/zinc sulfide (Cd 125 m Te / ZnS) nanoparticles were targeted to mouse lung with antibody to mouse lung endothelium and quantified using radiological histology in order to test the in vivo targeting efficacy of a nanoparticle–antibody (NP–mAb) system. The nanoparticles were linked to either a monoclonal antibody to mouse lung thrombomodulin (mAb 201B) or a control antibody (mAb 33), and injected into groups of 6-week-old Balb/C female mice. Animals were sacrificed at 1, 4, 24, 72 and 144 h post-injection, and biodistribution in major organs was determined. Full body microSPECT/CT imaging was performed on a pair of mice (experimental and control) providing visual confirmation of the biodistribution. The Cd 125 m Te / ZnS NPs conjugated to mAb 201B principally target the lungs while the nanoparticles coupled to mAb 33 accumulate in the liver and spleen. These data provide, for the first time, a quantitative measurement of the in vivo targeting efficacy of an inorganic nanoparticle–mAb system.